1. Field of the Invention
The present invention relates to a process and equipment for the hot moulding of articles made of thermoplastic material.
2. State of the Art
The invention has been developed in particular for the moulding of panels for lining the interiors of motor vehicles. A conventional technology for the production of lining panels involves heating of at least one plate of thermoplastic material to a plasticizing temperature and setting the plate, together with a possible upholstery sheet, between two half-moulds of an apparatus for hot moulding, which are provided with respective moulding surfaces set opposite one another. Hot moulding involves the application of pressure on opposite surfaces of the plate in a plastic state, thus bestowing on the plate the desired shape. Normally, during moulding of the plate, also an upholstery sheet is applied on one surface of the plate itself When panels are produced for internal lining of motor vehicles, it is often necessary to fix, on the rear surface of the panel, one or more inserts forming an anchoring seat for a fixing means, such as a screw a snap-in pin, or the like. Normally, these inserts are produced by injection moulding separately from the hot moulding of the panel, and are subsequently fixed by welding on the rear surface of the moulded plate. Alternatively, the inserts produced by injection moulding may be fixed on the plate during hot moulding of the plate itself. In this case, the inserts are positioned in the hot-moulding equipment and are mechanically anchored to the plate during moulding.
The latter approach requires injection-moulding equipment independent of the hot-moulding equipment and involves an operating step in which the inserts are fixed onto the moulded plates, or else a step in which the inserts are positioned on the moulding equipment.
The object of the present invention is to provide a process and equipment for hot moulding of articles made of thermoplastic material, which will enable a reduction in the cost of the finished articles and a simplification of the production cycle.
According to the present invention, the above subject is achieved by a process and equipment having the characteristics specified in the claims.